Credit

Caption

Goblet cell in the lining of the nasal epithelium, coloured transmission electron micrograph (TEM). The goblet cell (turquoise) is full of mucus granules (green) and is surrounded by microvilli (orange) coated columnar epithelial cells (brown). The squamous nasal epithelium is made up of both ciliated (not seen) and microvilli coated columnar epithelial cells. Goblet cells are interspersed through this nasal epithelial layer. The goblet cells secrete mucus onto the surface of the nasal cavity (where the surface of the ciliated and microvilli coated columnar epithelial cells are exposed in the nasal cavity). Cilia and microvilli become coated with sticky mucus that helps trap foreign objects, such as dust, bacteria and pathogens, preventing them from entering the lungs. Coordinated, wave-like beating of the cilia propels the mucus to the back of the nasopharynx, where it is swallowed, thus removing foreign objects. Magnification: x2,030 when shortest.